This invention is related in general to the field of telecommunications equipment. More particularly, the invention is related to a triggerless number portability system and method.
Local number portability (LNP) is a relatively recent development in the telephone industry that allows a telephone service subscriber to change the telephone company or carrier providing the service without having to change telephone numbers. To enable local number portability, centralized regional entities called the number portability administration center (NPAC) have been established to store and update the location and associated data on the ported telephone numbers residing in the telecommunications switching network. In addition, each service provider is required to provide a local service management system (LSMS) that will accept from NPAC the data related to telephone numbers and associated LNP data and then propagate them to signal transfer points (STPs) serviced by each service provider.
In most cases, an LNP database query is required for call delivery in an LNP environment. The query consists of a Signalling System Number 7 (SS7) message sent from a query-originating switch to a network database to obtain the necessary routing information to route the call. Local number portability (LNP) is the process by which the dialed telephone number is translated by a database lookup process at the signal transfer point to a local routing number (LRN) of the destination. When a customer places a call to a ported number, the dialed number is sent in an SS7 query message to the LRN application residing in a signal transfer point. The LRN application replies by returning the LRN corresponding to the dialed telephone number, and the LRN is then used by the querying switch and subsequent switches to route the call to the network element that has the same network routing address (NRA) as the LRN.
Many wireless service providers do not have number portability routing capability, so they rely on another service provider to look up ported telephone numbers in its LRN database. In most instances, the service provider charges the wireless service provider significant fees for performing this service and substantially driving up the cost for wireless calls.
Accordingly, there is a need for a way to allow a service provider to query the LNP database without using an LNP query.
In accordance with the present invention, a triggerless local number portability system and method are provided which eliminates or substantially reduces the disadvantages associated with prior solutions.
In one aspect of the invention, a method of providing local number portability capability includes the steps of capturing all initial address messages transmitted on at least one predetermined SS7 link set to a signal transfer point, where each initial address message has a called party number parameter containing a dialed telephone number. A determination is made as to whether a predetermined FCI bit is set to one or zero and in response to the predetermined FCI bit being set to zero, the following steps are performed. A local number portability database lookup is done using the dialed telephone number to obtain a corresponding local routing number. If an LRN is found, the local routing number is then inserted into the called party number parameter of the initial address message, and the dialed telephone number is inserted into a generic address parameter of the initial address message. Whether or not an LRN was found, the predetermined FCI bit is then set to one. The initial address message is then sent to a destination specified by the information in the called party number parameter (CdPA).
In another aspect of the invention, a signal transfer point providing triggerless local number portability capability is provided. The signal transfer point captures all initial address message transmitted on a link set to the signal transfer point, where each initial address message has a called party number parameter containing a dialed telephone number A determination is made as to whether a predetermined FCI bit is set to one or zero and in response to the predetermined FCI bit being set to zero, the following steps are performed. A local number portability database lookup is done using the dialed telephone number to obtain a corresponding local routing number. If found, the local routing number is then inserted into the called party number parameter of the initial address message, and the dialed telephone number is inserted into a generic address parameter of the initial address message. Whether or not the LRN is found, the predetermined FCI bit is then set to one. The initial address message is then sent to a destination specified by the information in the called party number parameter.
In yet another aspect of the invention, a method of providing local number portability capability to a service switching point includes the steps of capturing all initial address message sent by the service switching point, where each initial address message having a called party number parameter containing a dialed telephone number, and determining whether a predetermined FCI bit is set to one or zero. In response to the predetermined FCI bit being set to zero, a local number portability database lookup is performed using the dialed telephone number and a corresponding local routing number therefor is obtained. If found, the local routing number is inserted into the called party number parameter of the initial address message, and the dialed telephone number is inserted into a generic address parameter of the initial address message. Whether or not the LRN was found, the predetermined FCI bit is then set to one. Finally, the initial address message is sent to a destination specified by the called party number parameter.